Trauma is the leading cause of death in Americans between the ages of one and forty years. Shock lung, the pulmonary insufficiency that can follow severe trauma and shock, is a major cause of death in patients who are initially successful resuscitated from their injuries. The objective of this proposal is to analyze the role of arachidonic acid metabolites (including the native prostaglandins) in the pathogenesis of shock lung. The Staub preparation which allows access to pure pulmonary lymph provides insight into lung fluid dynamics and allows assay of arachidonic acid metabolites in a representative of lung interstitial fluid, i.e., in lung lymph. The sheep are subjected to a combined hemorrhagic-septic insult and the metabolism and pharmacology of arachidonic acid is studied.